Explicație pas cu pas:
[tex]7. \: a) \frac{12}{ \sqrt{3} } + \frac{15}{5 \sqrt{3} } - \frac{21}{7 \sqrt{3} } + \frac{18}{ \sqrt{3} } \\ rationlizam \\ \frac{12 \sqrt{3} }{3} + \frac{15 \sqrt{3} }{15} - \frac{21 \sqrt{3} }{21} + \frac{18 \sqrt{3} }{3 } \\ 4 \sqrt{3} + \sqrt{3} - \sqrt{3} + 6 \sqrt{3} \\ = 10 \sqrt{3} [/tex]
